EDEN PRAIRIE, Minn. -- The Minnesota Vikings' new offense needs all the work they can get, but coaches aren't rushing when it comes to preseason action.

Quarterback Donovan McNabb and the first string will play "at least a quarter, maybe a quarter and a half" on Saturday at Seattle, coach Leslie Frazier said on Wednesday.

That's fairly standard for a second exhibition game and about the same amount of action most starters got last week at Tennessee, although that was in part a result of only running nine plays in the first quarter.

The starters gained three first downs and 51 yards over two drives against the Titans, while the offense as a whole netted 248 yards, 14 first downs and only three points, on a Ryan Longwell field goal in the third quarter.

"The most important thing for us as an offense is to just continue this thing rolling," McNabb said. "Try to get in the end zone, try to put some points on the board, get some big plays, move the chains, converting on third downs -- those are things that obviously we can work on in this particular game that we'll, kind of, benefit from in the season."

The absence of at least one starting skill-position player (tight end Visanthe Shiancoe) and perhaps another (receiver Percy Harvin) on Saturday won't expedite that process. McNabb also figures to be working behind an altered offensive line, with some combination of Anthony Herrera, Scott Kooistra and perhaps Ryan Cook replacing Chris DeGeare at right guard.

Asked how timing is coming along, McNabb said, "I think we're very close. But again, it really comes back to consistency. It's just running the right routes at the same depth. As a quarterback, putting it in that some position where he can come out of his break and expect the ball there. Knowing how some people's speed is a lot different than others on 'go' balls or skinny posts, whatever it might be. Those are things we're learning."

Corners make plays

Griffin's interception was another positive sign in his recovery from a second knee reconstruction. He sunk in zone coverage and had plenty of time to pounce when Ponder threw late for Jaymar Johnson on a corner route.

The plan is for Griffin to play "at least a series" on Saturday, Frazier said -- his first game action since his injury on Oct. 11 against the New York Jets.

Sherels' interception was more impressive. He dived in front of veteran receiver Michael Jenkins on a comeback route and sent the defensive sideline into a raucous celebration.

"We'll see how he feels (Thursday)," Frazier said. "You've got to consider a torn ACL and coming back out here and moving around, it's going to be a little bit sore, but not to the point where we can't give him a little bit more."

Rookie linebacker Jonathan Gilmore, who left Tuesday's practice after complaining of chest pains, passed a battery of tests and was back on the field on Wednesday.

Return games

Special teams coordinator Mike Priefer said he hopes to get each of his punt-return candidates two chances on Saturday, although game flow will dictate that.

Sherels gained 9 yards on one of his two chances at Tennessee, but Jaymar Johnson made the biggest splash, getting the sideline for a 40-yard chunk in the fourth quarter.

"It was well-blocked," Priefer said. "I thought (Johnson) did a nice job of finding the seam. We have some young guys out there that need to learn how to finish plays, which is what we worked hard on this week -- and then we might even score."

Lorenzo Booker was deep for the Titans' first two punts, but one was a knuckleball that dropped behind him and the other went out of bounds.

Talking Tarvaris

Frazier said he wishes "nothing but the best" for former Vikings quarterback Tarvaris Jackson, who is expected to start against his old team on Saturday.

McNabb kept in contact with Jackson in recent years, too, and said he's "excited about his opportunity in Seattle. I thought it would come a little earlier being here in Minnesota, but yet still you've just got to be patient and that's one thing that I tried to stress with him, patience.

"I think, as a player, you want it to happen now. We all thought it would happen, but obviously when they brought Brett (Favre) in things changed a little bit. But you know, in this game, things are not always going to go your way, and I obviously learned that last year (in Washington). You just have to put it behind you and move forward."

• Seth Olsen split first-team reps at left guard with Steve Hutchinson, who has been battling a sore shoulder and pectoral muscle.

• At Frazier's invitation, former NFL safety Aeneas Williams addressed players after practice and was scheduled to talk again to the team's rookies during a "life skills" session later in the afternoon. The two have known each other since Frazier was an intern under Buddy Ryan with the Arizona Cardinals in the 1990s and Williams was in the early stages of his 14-year career. "I don't know if there is a great example of how to handle the NFL, along with balancing life off the field," Frazier said.

• The Vikings will hold one more practice on Thursday plus a pair of walkthroughs before departing for Seattle on Friday afternoon.